The spinal column of a patient includes a plurality of vertebrae linked to one another by facet joints and an intervertebral disc located between adjacent vertebrae. The facet joints and intervertebral disc allow one vertebra to move relative to an adjacent vertebra, providing the spinal column a range of motion. Diseased, degenerated, damaged, or otherwise impaired facet joints and/or intervertebral discs may cause the patient to experience pain or discomfort and/or loss of motion, thus prompting surgery to alleviate the pain and/or assist motion of the spinal column.
Methods of treating spinal column disorders include installing a spinal stabilization system to stabilize a segment of the spinal column. One conventional spinal stabilization system includes securing a rigid rod between two or more vertebrae with pedicle screws or other vertebral anchors. Another technique utilizes a less rigid connecting element to provide a more dynamic stabilization of the affected segment of the spinal column. One example of a dynamic stabilization system is the DYNESYS system available from Zimmer Spine, Inc. of Minneapolis, Minn. Such dynamic stabilization systems may include a flexible, tubular spacer positioned between pedicle screws installed between adjacent vertebrae. The spacer is positioned between the pedicle screws and a flexible cord is threaded through the spacer. The flexible cord is secured to the heads of the pedicle screws by set screws, thereby retaining the spacer between the pedicle screws while cooperating with the spacer to permit mobility of the spine.
Some surgical situations may make installation of a spinal stabilization system using known installation systems difficult and/or impracticable in some circumstances. For instance, in a surgical situation in which pedicle screws are anchored to adjacent vertebrae in a converging orientation, it may be difficult to implant a stabilization system between the converging pedicle screws using known installation systems. Additionally and/or alternatively, it may be desirable to facilitate docking of an installation tool with a pedicle screw and/or make alterations to an installation tool without undocking the tool from the pedicle screw. Therefore, alternative systems and associated methods for installing a vertebral stabilization system are desirable.